Here is the solution:
So for every 1 boxes = $1.125 (1 1/8)
They have sold 75 boxes already so, 75 x $1.125 = $84.375
Tony needs to raise $180 so, $180 - $84.375 = $95.625
Tony still needs $95.625 more, so $95.625/$1.125 = 85
Therefore, tony needs to sell 85 more boxes in order to reach $180.